This invention relates to improvements in a fuel hose to be used for an automotive vehicle or the like, and in a method of producing the fuel hose, and more particularly to the improvements in the fuel hose to be used in an evaporative emission control system.
In general, fuel hoses for an automotive vehicle take a multiple layer structure including layers formed of rubber and synthetic resins excellent in fuel permeation resistance in order to prevent emission of fuel vapor. An example of such fuel hoses is disclosed in Japanese Patent Provisional Publication No. 8-108499 and has a three layer structure including an innermost layer, a intermediate layer and an outermost layer. The innermost layer is formed of an elastomeric material such as acrylonitrile-butadiene copolymer rubber (NBR) or fluororubber (FKR) in order to ensure the sealing ability to a connection-partner pipe and the pull-out force of the fuel hose. The intermediate layer is formed of fluororesin such as tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride copolymer (THV) so as to serve as a barrier layer. The outermost layer is formed of epichlorohydrin rubber (ECO) or a blend (NBR/PVC) of acrylonitrile-butadiene copolymer rubber.